Using Win2D Samples Gallery code fails

srfpala 111 Reputation points

Running Win10 with VS2019CE using a Win2D example particles
public class Particle // Taken from Particle.cs
This line of code
this.Rotation = Utils.RandomBetween(0, (float)Math.PI * 2);
causes a CS0103 error
The name 'identifier' (i.e. Utils) does not exist in the current context.
What should I do ?
VS2019 a Project Solution code for Win2D Gallery Particle System would be most helpful

Universal Windows Platform (UWP)
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